1. Field of the Invention
This invention relates to a camouflage pattern, and techniques that can be used to create a camouflage pattern. More particularly, the invention relates to a camouflage pattern used on fabric based structures that in combination with certain dyes, fabrics, and materials as well as certain printing techniques, provides improved concealment for military personnel, vehicles, and other equipment in a range of tactical environments. Also, the invention pertains to a camouflage system used on non-fabric equipment. In addition, the camouflage pattern is useful in the civilian sector for fashion, as well as sportsman. This invention combines principles of human perception, natural camouflage, and psychophysics to create two pattern elements of a macro-pattern and a micro-pattern combined into a single configuration: one to disrupt the features of the subject target, the other to match the subject target to the characteristics of the background. The combinations of this invention provide counter surveillance from visual and near-infrared detection for combat utility uniforms and equipment.
2. Related Applications
Design patent application Ser. No 29/143,340 titled xe2x80x9cunited states marine corps combat utility uniformxe2x80x9d filed Jun. 13, 2001.
Design patent application Ser. No. 29/143,683 titled xe2x80x9ccamouflage pattern for sheet material and uniformsxe2x80x9d filed 19 Jun. 22, 2001.
Provisional patent application No. 60/312,743 titled the same as above, filed Aug. 17, 2001 from which filing date benefit is claimed.
3. Description of the Prior Art
Camouflage is an art in the process of becoming a science. Camouflage, also called protective concealment, is a means to disguise a subject, whether animate or inanimate, in plain sight so as to conceal the subject from something or someone. Beginning with Abbott and Gerald Thayer in the late 1800""s and Pycraft in the 1920""s, camouflage evolved from a study of naturalistic observations of organisms in their complex environments to designs that purposely effect perception. The basic canon of natural camouflage includes xe2x80x9cevolved tacticsxe2x80x9d such as mimicry (contrived similarity to background features, like the walking stick bug), countershading (lightened ventral surfaces to combat the contrast of shadow), and disruption (Thayer""s xe2x80x9cruptionxe2x80x9d), the breakup of boundary features or internal structures.
Thayer noticed that the coloring of many animals graduated from dark, on their backs, to almost white on their bellies. The gradation from dark to light breaks up the surface of an object and makes it harder to see the object as one thing. The object loses its three-dimensional qualities and appears flat. The ratio of dark coloration to light coloration can mean the difference between success and failure of a design. Thayer called this xe2x80x98ruptionxe2x80x99xe2x80x94the development of patches of light and dark covering that served to break up the outline of the animal.
However, strategies based on natural observations often fall short of military requirements. There are two reasons for departing from the xe2x80x9cnaturalxe2x80x9d approach. First, animal coloration is often idiosyncratic and keyed to narrow co-evolution histories of predator and prey in a specific econichexe2x80x94that is, the zebra""s stripes tell us more about the visual system of the lion than about usable principles of military camouflage. Second, organisms are limited in the strategies (patterns) they can xe2x80x9cemploy.xe2x80x9d The coloration patterns of animals reflect survival probabilities over a long period of time passed on genetic advantage. However, animals do not xe2x80x9cdesignxe2x80x9d their appearance; the process is passive and represents genetic exploitation of random mutations. In addition, the processes by which natural patterns develop are constrained by biology.
Murray (1992) describes, for example, the process by which local interaction between two populations of color producing cells (melanophores) create different categories of patterns (stripes, spots, blotches, etc.) reminiscent of standing waves of different frequencies in metal sheets. It is significant requirement for this invention that a particular frequency or local melanophore interaction may produce a pattern that interrupts internal symmetry axes. Biological entities have the disadvantage of not being able to produce an animal with both spots and stripes, or with complex patterns of certain types.
Deliberate military camouflage as well as sportsman and fashion patterns does not suffer from these limitations. It is useful as well to remember that animals choose to inhabit certain fairly narrow econiches which in turn allows camouflage xe2x80x9cstrategiesxe2x80x9d very specific to particular places and backgrounds. Military forces do not have this luxury, and must adopt strategies more generally effective across a range of terrain and environmental conditions to which they may be deployed.
Brassey""s Book of Camouflage by Tim Newark traces some of the history of camouflage. In 1812, some of the first experimentation done with camouflage found that the color that blended in the best in the wild was gray. In 1857, one of the first true uses of camouflage occurred when British soldiers dyed their white tunics and belts tan, or khaki (which means literally xe2x80x9cdustyxe2x80x9d colored), to blend in with the environment in India. The first section de camouflage in military history was established in 1915 by the French, under the command of an artist. Thereafter, comparable units were used by the British and Americans, and, to lesser extent, by the Germans, Italians, and Russians. These units were largely made up of camoufluerss who in civilian life had been artists of one kind or another, including fine artists, designers, and architects. As a result, participants on all sides of the conflicts used hundreds of artists during both World Wars. These artists acted as military or civil defense camouflage experts. Included in this group were such familiar names as Jacques Villon, Franz Marc, Arshile Gorky, Thomas Hart Benton, Grant Wood, Laszlo Moholy-Nagy, and Oskar Schlemmer.
Artificial camouflage patterns of some sophistication appeared in the 1914-1918 time frame propelled by advances in weapons and tactics that accompanied the First World War. Thayer designed some of these patterns. Others were designed by a variety of daring and empirical innovators. The designers tended to rely on bold disruption, deception techniques (e.g. painting a large bow wave on a slow vessel to deceive submarine observers as to their actual velocity and direction), as well as traditional blotch and splinter (sharp-edged, polygonal patterns) approaches.
While the wartime use of camouflage is by no means a modern invention, its importance became magnified during World War I because of the use of airplanes and aerial photography. The Korean War saw the introduction of night vision devices, which added the need to disrupt the human form not only in the visible but also in the near infrared range of the spectrum. Humans see a wide color spectrum called the visible range, and when aided by night vision devices, humans can also see into the near infrared range. The problem of disrupting the human form in both the near-infrared and visible ranges is only a military problem that has no parallel in the natural world. Adding to the complexity is that dry and wet conditions change reflectivity of surfaces changing the xe2x80x9chidingxe2x80x9d characteristics of most patterns under different light conditions.
Interest in camouflage declined through the 1950s because of advances in fire control and target acquisition technology. Also, experience showed that most camouflage measures simply did not work very well. The visual system simply overpowered most measures.
In the late 1960""s and 1970""s, there was a resurgence of interest in camouflage. In the area of camouflaging combat vehicles, Sweden adopted a xe2x80x9csplinterxe2x80x9d pattern keyed to the colors predominant in Scandinavia. Germany experimented with novel boundary disrupting measures. Many countries simply applied camouflage as a matter of pride or decoration. Some of these designs had little practical counter-surveillance utility, but looked somehow xe2x80x9cmartial.xe2x80x9d
In the United States, the war in Viet Nam occasioned the issue of battle dress uniforms using a woodland color pattern that was designed by the U.S. Army Engineering Research and Development Laboratory as early as 1948. Though designed by the Army, it was rejected by that service and adopted instead by the Marine Corps. By the late 1970""s, a general desert camouflage appeared for uniforms. By the middle of the 1970""s, combat vehicles and other equipment acquired a four-color camouflage pattern designed by the U.S Army Mobility Equipment Research and Development Center (MERDC; now BRDEC). This pattern was widely used from 1974 until the 1980""s, when it was replaced by a 3-color NATO standard pattern.
Camouflage Pattern
For the human form, camouflage is used by hunters and by the military. For hunters, it is sufficient to disrupt the human form with a pattern because many animals are colorblind so, it is only necessary to xe2x80x9cblendxe2x80x9d into the shades of gray created by the background of the terrain. Colors within that terrain are not as critical. For military applications, color is an additional issue that must be considered.
Two significant deficiencies common to most camouflage pattern measures is that most pattern measures address either the configuration of the target to be hidden, or the nature of the background into which the target must blend. This limits the usefulness and robustness of a concealment measure since both objectives must be answered if the target""s signature is to be significantly reduced for the observer. There have been many approaches trying to address both camouflage patterns in general and military or paramilitary applications of camouflage in particular. The most common appearance of military camouflage are various forms of curving shapes in three to four natural xe2x80x9cearth tonexe2x80x9d colors. Hunter camouflage takes the form of a mimic of trees, bark or bushes. Mathews in U.S. Patent No. Des. 425,709 teaches a camouflage design in the form of bushes. Kolpin, in U.S. Patent No. Des. 297,076 shows a bark or rock like pattern. Yacovella in U.S. Pat. No. 4,656,065 teaches a pattern and color combination that mimics rough bark of a tree. Hollinger, in U.S. Pat. No. 5,675,838 carries this theme a step further by teaching two different patterns printed on one set of clothing to account for vertically and horizontally growing plant life. Lehman, in U.S. Pat. No. 5,972,479 describes a method of creating or forming these mimic camouflage patterns. The process includes photographing one or more environments, entering the photographs as graphics into a computer to create a composite picture, separating the colors in the composite picture into a series of color prints, creating screens for each major color, and finally rotary screen printing the composite onto sheet material. This technique is a standard printing process for fabrics in general and camouflage in particular. The issue with mimic patterns is that they are site specific or geographically limited.
For military applications, the mimic of a particular setting is inadequate. The military needs camouflage that will be adaptable in many different environments and under different weather conditions with the minimum number of uniform sets. In addition, the military needs a camouflage pattern that works well in the visible as well as in the near-infrared range of the spectrum when using night vision devices.
Many military patterns, on the other hand, ignore the nature of the background (except as regards gross color distributions), concentrating on the Thayer principle of disruption of boundaries. Each of these approaches is somewhat less than half the answer. Conway, in U.S. Pat. No. 5,077,101, describes camouflage for tanks and other vehicles by using a three-color paint that helps to mask infrared emissions. The paint relies heavily on the inclusion of carbon in the dye. Carbon can also be incorporated into the fiber itself for substrate or sheet material on which a camouflage pattern is printed. Such a process is described by Weingarten in U.S. Pat. No. 4,095,940, where carbon is incorporated into the fiber and the sheet material is then cross-dyed or over-printed with standard dyes that are compatible with that type of fiber as used in traditional camouflage patterns to provide adequate near-infrared protection properties. Clarkson, in U.S. Pat. No. 5,798,304, describes an interesting camouflage uniform for uniformed law enforcement that shows a solid color under visible lighting conditions and a camouflage pattern in the near-infrared range.
Conner in U.S. Pat. No. 5,985,381 took a different approach. Conner suggests a mimic type pattern (leaves of an eastern forest) coated with photochromic and/or heat sensitive materials so the printed pattern will change color under different light and temperature conditions.
One innovation appeared in 1976 that applied a more scientific spin explaining the reasons camouflage worked, O""Neill et al. (1977a,b). This innovation was called xe2x80x9cDual-Texxe2x80x9d or dual-texture. Initially, Dual-Tex was a modification of the MERDC 4-color vehicle pattern, where a band of higher, denser texture was added by the simple expedient of coarse quantization. This means that a larger pattern was decomposed into pixel-like square elements while keeping the larger element. This was like xe2x80x9cadding leaves to treesxe2x80x9d without removing the tree. The result was a macropattern that disrupted the shape of the target making it hard to recognize, and a micropattern that matches the texture of the background, making it hard to detect (hence xe2x80x9cDual-Texturexe2x80x9d). These two elements address the two visual tasks that face an observer detecting a target against a background (technically, detecting an anomaly in the optic array), and then recognizing (or identifying) the anomaly as a target or a false alarm. These tasks are served by two more or less distinct visual pathwaysxe2x80x94the ambient (or tectopulvinar) and the focal (or geniculostriate). These have been described as the xe2x80x9cwhere is it?xe2x80x9d and the xe2x80x9cwhat is it?xe2x80x9d systems.
The Dual-Tex measure was subjected to test and evaluation at the United States Military Academy using photo-simulation techniques (O""Neill et al., 1977a), and at Aberdeen Proving Ground using human observers against painted test vehicles at tactically appropriate ranges (O""Neill et al., 1977b,c) The measure was tested informally in various locations, and in 1978 was adopted by the 2nd Armored Cavalry Regiment in Europe (where it continued in use until the adoption Army-wide of the current 3-color pattern). It was formally subjected to troop test by the Combat Development Experimentation Command shortly afterward (CDEC, 1979). An application of the Dual-Tex concept was published in the November/December 1977 issue of Armor Magazine.
Military patterns that address disruption of the target shape, as opposed to background match, concentrate on the boundary features of the target. This is a misconstruction of what constitutes the visual, as opposed to the physical features of the target. The Dual-Tex macro-pattern component, as an exception, evolved from a traditional boundary-disrupting configuration to a unique and more effective approach.
Blum (1967, 1973, 1974, 1978) demonstrated a new non-Euclidean geometry of biological form based on internal symmetries of shapes. Psotka (1978) showed that the observer""s visual attention tends to lie along the symmetry axes of a shape rather than along the boundary or at the center (as traditionally assumed). O""Neill (1982) demonstrated the effect of a local interaction in the optic array that draws the attention of the observer, and may assist in recognizing and encoding shapes in the visual cortex. O""Neill (1986) modified the Dual-Tex pattern to include a macro-pattern keyed to the symmetry axes instead of the boundaries in a test of the effects of camouflage measures on the ability of a gunner to track a moving target. The combination of the target disrupting macro-pattern and the background-matching micro-pattern is the essential characteristic of the Dual-Tex type measure. No previously known or currently known camouflage pattern measure appears to address both these factors (disrupting the target and matching the background) effectively for a broad spectrum of terrain and environmental conditions needed for military operational effectiveness.
The micro-pattern of the Dual-Tex measure was designed to match the texture of the background in a tactical environment, defined as the spatial frequency spectrum. The micro-pattern matches the spatial frequency spectrum of the environmental background. It mimics the size components of the background. The role of spatial frequency in human vision and pattern recognition has been demonstrated experimentally since 1969 (e.g., Blakemore and Campbell, 1969; Julesz, 1980; Maffei and Fiorentini, 1980; Ginsburg, 1978, 1980). O""Neill (1988) demonstrated the role of spatial channels in detecting military targets. Dual-Tex pattern employs a quantization method to decompose a macro-pattern (q.v.) by the technique of digitizing the macro-pattern to add appropriate bands of spatial frequency xe2x80x9cnoisexe2x80x9d that mimics the presumed tactical background.
The Canadian National Defense Force came to realize that it was not necessary to have curved sections of color to form a camouflage pattern. The Canadians designed and began fielding the Canadian disruptive pattern (CADPAT), which consists of shapes having relatively straight sides. Josephs, in U.S. Pat. No. 6,061,828, also suggests a camouflage pattern using what Josephs calls rectilinear shapes. Josephs relies on rather large splotches of color in at least six sided splotches with opposing sides being parallel to form a pattern. Josephs appears most interested in the xe2x80x9cfashionxe2x80x9d attraction of camouflage rather than its utilitarian application. The only advantage of straight-sided figures is that it simplifies computer printing. The US Marine Corps evaluated some 60 existing patterns in house. Field-testing revealed that none of the existing patterns provide maximum concealment possible given today""s printing and material technologies as well as pattern concepts.
Fabric, Printing and Garment Treatments:
Historically, military uniforms were made of heavy cotton twill or duck fabric. This is also true of the modern fatigue or utility uniform. The heavier the fabric the more durable it was. These types of fabrics were hot to wear, became heavier when wet and were slow to dry. Cotton fabrics rapidly look like they were xe2x80x9cslept inxe2x80x9d even when heavily starched. Pure synthetic fibers had a good wear life and could be made permanent press, but the fabric tended to be hot and not adsorb sweat. In addition, many synthetic fibers reflected both visible and infra red light. In other words, synthetic fibers are shiny. Blending cotton with synthetic fiber, such as nylon, increases the fabric""s strength without increasing weight. Uniforms and clothing made from these fabrics wear better than those made from the traditional 100 percent cotton fabrics. They also have advantages of drying rapidly, and maintain a sharp military appearance longer. Finding the correct balance of fiber composition, weave, weight, and ability to take the needed dyes was a complicated empirical problem.
Printing, represents another challenge. While there are numerous types of dyes and pigments, all of which are chemically compatible with specific fiber types, they can not be used interchangeably. Each different class of dye also has certain performance characteristics. Acid dyes are compatible with nylon fiber and are very colorfast, but in the near infrared, generally, they are too light and bright for military camouflage purposes. Vat dyes are used to dye cotton fabrics. They are very colorfast, but in the near infrared, generally, they are too dark. Disperse dyes are compatible with polyester, however, they are not available in the colors required to meet military camouflage specifications, they are not very colorfast, and they are light and bright in the near infrared.
Hodge et al., in U.S. Pat. No. 5,074,889, teaches a method and describes materials for printing aromatic polyamide (aramid) fabrics with acid dyes. The treatment is specifically designed to print or overprint the sheet material with an acid dye for camouflage patterns. A problem still remains. The problem is achieving the objectives of a durable, serviceable uniform with concealing characteristics in the visible and near infrared. The problem requires a disruptive pattern that can be used for a wide range of applications from paint patterns on tanks, through uniforms that is an improvement on the good beginning of the prior art.
Accordingly, an object of this invention is the creation of a camouflage pattern measure based on the functioning of the human visual system, addressing both disruption of the subject target shape and matching of the spatial characteristics of the environment.
Another object of the invention is a pattern which is empirically developed and subsequently defined by a mathematical algorithm that is optimized for different environments by computer aided devices.
A further object of this invention is a pixel pattern that provides improved disruption of a subject over existing patterns.
Yet another object of this invention is the creation of a camouflage pattern printed on a surface such as fabric of uniforms and equipment or combat vehicles that will provide improved concealment in both visible and near-infrared range of the electromagnetic spectrum.
A further object of this invention is integrating the fabric, acid dyes and overprinted vat dyes, and functional finishes together with a specific empirically derived pixel pattern providing improved results in the visible and near-infrared spectrum range for fabric based subjects.
Yet another object of the invention is a camouflage pattern which gives effective camouflage results under both wet and dry conditions.
A further object of this invention is a system resulting from a combination of materials, dyes, printing methods, pattern and design features relating specifically to uniform design that builds a xe2x80x9csystemxe2x80x9d which provides U.S. Marines a combat utility uniform with significant advantages over currently available similar systems.
A further object of this invention is a fabric that provides improved camouflage advantages when combined with specific dyes and printed in a specific pattern.
Again, an object of this invention is a human engineered uniform having improved wear characteristics and improved protective protection for the user.
These and additional objects of the invention are accomplished by a camouflage system to be used for both military uniforms and equipment. Also, the system can be used for civilian applications, particularly with sportsman hunters. The system provides camouflage in both the human visible light range and the infrared light range. The system depends on the use of a macro-pattern resulting from a repeat of a micro-pattern. On fabric, the results are achieved by printing a macro-pattern that disrupts the sensed shape of the subject and a micro-pattern that blends the subject into the background. The repeat size of the micro-pattern produces the macro pattern. The reflectance of the printed material is comparable to the negative space surrounding a subject so the subject does not appear too dark or too light (out of place). The variation in the lightness between wet and dry printed fabric is not greater than 17-28%. The fabric can be formed into uniforms and other fabric equipment.